Remote Access System, Remote Access Method, and Medium Containing Remote Access Program

1. A remote access system, comprising: a pair of computers, with a first computer coupled with a second computer at least by way of radio transmission in a network; said first computer has an access code registered with it for remote access, is capable of accommodating a transportable and removable nonvolatile memory, encrypts said access code by a prescribed method, and stores said access code in the nonvolatile memory; and said second computer is capable of accommodating said nonvolatile memory, decrypts said encrypted access code when the nonvolatile memory is plugged into the second computer, and accesses said first computer by using the decrypted access code each of said pair of computers stores each of a first pair of key data in which data encrypted by using a first key data cannot be decrypted without using a second key data; the first computer encrypts said access code by using the first key data and stores it in said nonvolatile memory; and the second computer decrypts said access code by using the second key data; when remotely accessing said first computer, said second computer encrypts said access code by using said second key data and sends it out; and said first computer decrypts the encrypted access code by using said first key data, compares the access code stored in advance with the access code received, and conducts authentication.

2. A remote access system according to claim 1 , wherein said nonvolatile memory is a SmartMedia card.

3. A remote access system according to claim 1 , wherein said nonvolatile memory is a USB memory.

4. A remote access system according to claim 1 , wherein said one computer is installed in a motor vehicle.

5. A remote access system according to claim 4 , wherein said access code is at least based on a vehicle identification number.

6. A remote access system according to claim 1 , wherein said other computer's access code is based on an individual identification number of its CPU.

7. A remote access system according to claim 1 , wherein said other computer is a home server in which music data are stored.

8. A remote access system according to claim 1 , wherein said pair of computers are connected with each other through a home network system.

9. A remote access system according to claim 1 , wherein said pair of computers are connected with each other through the Internet.

10. A remote access system according to claim 1 , wherein said access code is generated at random when said nonvolatile memory is removed and is stored in both said one computer and said nonvolatile memory.

11. A remote access method of a network system, comprising: coupling a pair of computers capable of accommodating a mutually transportable and removable nonvolatile memory at least by way of radio transmission; a first computer has an access code registered with it for remote access, encrypts the access code by a prescribed method, and stores the access code in said nonvolatile memory; and a second computer decrypts said encrypted access code when the nonvolatile memory is plugged into the second computer, and makes the second computer possible to access said first computer by using the decrypted access code each of said pair of computers stores each of a first pair of key data in which data encrypted by using a first key data cannot be decrypted without using a second key data; the first computer encrypts said access code by using the first key data and stores it in said nonvolatile memory; and the second computer decrypts said access code by using the second key data; when remotely accessing said first computer, said second computer encrypts said access code by using said second key data and sends it out; and said first computer decrypts the encrypted access code by using said first key data, compares the access code stored in advance with the access code received, and conducts authentication.

12. A medium containing a remote access program for a network system in which a pair of computers capable of accommodating a mutually transportable and removable nonvolatile memory are connected at least by way of radio transmission, comprising: a first computer that has an access code registered with it for remote access, and achieves a function of encrypting the access code by a prescribed method and storing the access code in said nonvolatile memory; and a second computer achieves a function of decrypting said encrypted access code when the nonvolatile memory is plugged into said second computer, and accessing said first computer by using the decrypted access code each of said pair of computers stores each of a first pair of key data in which data encrypted by using a first key data cannot be decrypted without using a second key data; the first computer encrypts said access code by using the first key data and stores it in said nonvolatile memory; and the second computer decrypts said access code by using the second key data; when remotely accessing said first computer, said second computer encrypts said access code by using said second key data and sends it out; and said first computer decrypts the encrypted access code by using said first key data, compares the access code stored in advance with the access code received, and conducts authentication.